Find sum of all two digit whole numbers divisible by 2

1.	Find sum of all two digit whole numbers divisible by 2
Answer» Two digit no. divisible by 2=10,12,14......98a=10,d=2,l=98l=a+(n-1)d98=10+(n-1)298=10+2n-298=8+2n98-8=2n2n=90n=45Sn=n/2{2a+(n-1)d}Sn=45/2{2×10+(45-1)2}Sn=45/2{20+44×2}Sn=45/2{20+88}Sn=45/2×108Sn=45×54Sn=2436

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